Tetris (Russian: Те́трис, pronounced [ˈtɛtrʲɪs]) is a Soviet tile-matching puzzle video game originally designed and programmed by Alexey Pajitnov. It was released on June 6, 1984, while he was working for the Dorodnicyn Computing Centre of the Academy of Science of the USSR in Moscow. He derived its name from the Greek numerical prefix tetra- (all of the game's pieces contain four segments) and tennis, Pajitnov's favorite sport.
It is also the first entertainment software to be exported from the USSR to the US and published by Spectrum HoloByte for Commodore 64 and IBM PC. The Tetris game is a popular use of tetrominoes, the four-element special case of polyominoes. Polyominoes have been used in popular puzzles since at least 1907, and the name was given by the mathematician Solomon W. Golomb in 1953. However, even the enumeration of pentominoes is dated to antiquity.
Sega released a Tetris game for the Japanese Mega Drive similar to their arcade release; however, the ensuing blitz of litigation ensured that it was hastily withdrawn. It is estimated that only between 3 to 8 copies were produced.